Talk:Event tree analysis

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comments[edit]

The first section did a very nice job introducing the basic concept of ETA, however I thought the wording was cyclical at times. I reworded the intro as such:

"Event Tree Analysis (ETA) is a quantitative modeling technique used to assess a network of events and their relative positive or negative probable outcomes as well as performing overall system analysis. This specific analysis method might best be conceptualized as a “forward, bottom-up” technique that begins with a single initiating event and subsequently through diverging event-paths until reaching the terminal outcome. ETA can [1] facilitate systematic identification of positive and negative consequences which may occur while also [2] provide quantifiable measures of exposure and effect of specific events within an activity system. ETA can be applied to a wide range of systems including but not limited to: nuclear power plants, spacecraft, and chemical plants. Utilizing ETA early in the design process may enable early identification of issues that could occur; this early identification allows may facilitate more proactive risk mitigation rather than reacting to problems/changes after they occur.[3] With this forward logic process use of ETA as a tool in risk assessment can help to prevent negative outcomes from occurring by providing a risk assessor with the probability of occurrence."

570mpt (talk) 15:09, 25 November 2013 (UTC)[reply]

— Preceding unsigned comment added by 69.5.134.46 (talk) 06:43, 25 November 2013 (UTC)[reply]

In the Introduction/Definition I miss the reference to risk assessment as an application for ETA. I think it is worth including it not only because this wiki is devoted to this topic but also because you have a complete section for it later on. In the Theory section I would recommend to define the concept loss end states. I wonder if the third bullet point of this section is correct. The second sentence of the second paragraph of Methodology might have a flaw: start at the left?. In this same paragraph when you refer to 1s I would include 1f as well and would recommend to see the attached graph. I don't quite understand the 4th step (bullet point) of this section: indentify intermediate events. I have looked for more information in one of your references C.A. Ericson (2005) and this point is clearer for me in the original paper: Identify the pivotal events. Perhaps, it might be worth changing it. Event tree Analysis I miss something at the beginning of the second sentence of this paragraph. In Advantages, I wonder if the fith bullet point is correct: ineffective or effective countermeasures? The 9th point says easy to lean perhaps it should say easy to learn. I wonder if it would be possible to include some names or references to complete the last point,i.e. some of the software available. Last but not least, I would recommend to include more references. It is always advisable for a wiki. By the way, I wonder if ETA is the same as Classifying tree analysis. I have learn about it in the article by Cox and Popken (2008) recommended in this course, and I think it is a very interesting tool in RA. Should it be the case, I would include a mention to this statistical method. You can find additional references in this paper and a mention to the rpart algorithm of the stastical software R. Perhaps, you can use it to improve your wiki. Good luck 570acm570acm (talk) 21:08, 9 November 2013 (UTC)[reply]

In the theory section, a probabilistic risk assessment use is stated; however in the methodologies and equation section there is a more deterministic approach described. Distinguishing between instances when a single point probability is used at each intervention point in a deterministic type assessment vs. a stochastic type assessment using probability distributions at each intervention point run with multiple iterations might be beneficial.

Perhaps examples of the use of varying complexity ETA’s could be added to the page.
How is uncertainty addressed when an ETA is conducted?

570ps (talk) 02:45, 11 November 2013 (UTC)[reply]

edits/recommendations Are "loss states" only considered to be negative actions and harm, although they can be naturally occurring? Like a flood for instance? Is that something that could be clarified?

Regarding the steps in the event tree analysis, are there programs that can be utilized to build the ETA? What is the simplest, easiest way to construct an ETA tree diagram?

Can you identify some real time, real life scenarios or applications where these ETAs and diagrams have been created, besides from the nuclear power plant study?

Good job, very detailed! Mark Rosmann570MAR (talk) 03:22, 20 November 2013 (UTC)570MAR (talk) 04:27, 14 November 2013 (UTC)[reply]

Your article looks good and there have been many comments. I have very few to add. Should Event Tree Analysis (ETA) is a forward, bottom up, logic modeling be logical modeling? Can you add a link to binary? Is something missing here? formating? Unexpected or collateral damage as a result of tests*Failure of mission I'm not sure what failute of mission is doing right there. Please check the format of your references. 570lah (talk) 22:57, 21 November 2013 (UTC)[reply]

EB Russell: This is well-written. In the HISTORY section you reference WASH-1400 – can you expand on that or include a link about it? In the section Event Tree Analysis In Risk Analysis: This sentence is a little confusing: Event Tree Analysis it is easy to see what pathway is creating the greatest possibility of failure for a specific system. — Preceding unsigned comment added by 570ebr (talk • contribs) 16:19, 21 November 2013 (UTC)[reply]

This is an interesting article and very well organized and written. Are you planning to simply add it in with the Event tree article? If not, a link should be provided at the least. The previous article specifically refers to Boolean logic, so maybe you should include this in the history or overview as well. It seems the first sentence of the history section would require a reference. I appreciate the diagram and the steps on how to perform ETA. Also, I like the section pertinent to risk analysis, although no references are given anywhere in that paragraph. The advantages and limitations may be better listed as a table as opposed to bullet points. Good work! Langleym (talk) 16:51, 21 November 2013 (UTC)[reply]

Looks great! Good organization, good use of wiki links, good picture of an event tree! Plus very concise but thorough, I think the bullet-points helped with that. The strengths and limitations sections were a good addition for anyone trying to decide if they want to use one. I like the inclusion of the "This was/is the part of an educational assignment"...may have to include that in mine! 570ADM (talk) 22:00, 22 November 2013 (UTC)[reply]

Adhithiya Charli Comments : Very interesting article and since I have not heard of ETA , it was a very good learning for me ! The steps for performing the ETA was very beneficial in understanding the concept. Good job ! Nice Topic ! - 570mac (talk) 19:21, 23 November 2013 (UTC)[reply]

The article is concise and well written, as a suggestion I would delete the 3 examples of software since it could be considered as spam. I would only note the existence of the same and I will allow to the "users" to do their own research about this commercial services.570fmf (talk) 04:21, 24 November 2013 (UTC)[reply]

Jie Luo-

cool topic and really, really well thought out and organized article! just one suggestion, since this is kinda over my head: i remember that we had this one article on drug-resistant campylobacter in Danish pigs, it was by alban 2007, that had a really nice event tree detailing every possible scenario of resistant campylobacter transmission. it might be worth considering to have it here if you want to tie in with biological risk assessment.Mercapto7 (talk) 04:54, 25 November 2013 (UTC)[reply]

Yafei Wang

Your event tree analysis is very helpful for people who are taking hand doing an analysis. And also you introduced a software that should be of help. This event tree analysis should be a very broad topic and you introduced it very comprehensively although not very specifically. But that should be quite enough for this wiki entry.570wyf (talk) 19:54, 25 November 2013 (UTC)[reply]

Comment reply[edit]

In the Introduction/Definition I miss the reference to risk assessment as an application for ETA. I think it is worth including it not only because this wiki is devoted to this topic but also because you have a complete section for it later on.

I think that I would agree

In the Theory section I would recommend to define the concept loss end states.

I think that with my current edits it is easier to understand but I agree with your point.

I wonder if the third bullet point of this section is correct.

a loss or end state can be defined by the user those bullet points are just common end states.

The second sentence of the second paragraph of Methodology might have a flaw: start at the left?.

good catch!

In this same paragraph when you refer to 1s I would include 1f as well and would recommend to see the attached graph.

I agree

I don't quite understand the 4th step (bullet point) of this section: indentify intermediate events. I have looked for more information in one of your references C.A. Ericson (2005) and this point is clearer for me in the original paper: Identify the pivotal events. Perhaps, it might be worth changing it.

Using pivotal events/points is a preference as is intermediate events/points, I think that some people may understand it better one way or the other but I do see where you are coming from and I think that my added example may help the reader understand “intermediate events”. Let me know what you think about the change.

Event tree Analysis I miss something at the beginning of the second sentence of this paragraph.

I agree that was a little difficult to read

In Advantages, I wonder if the fifth bullet point is correct: ineffective or effective countermeasures?

Yes it could display effective countermeasures but the largest point as I have fixed is to display negative outcomes which would be associated with ineffective. I think that I will add effective as well though because that does make it sound better in my opinion.

The 9th point says easy to lean perhaps it should say easy to learn.

Again good catch!!

I wonder if it would be possible to include some names or references to complete the last point,i.e. some of the software available.

I agree I have added a section for software

Last but not least, I would recommend to include more references. It is always advisable for a wiki. By the way, I wonder if ETA is the same as Classifying tree analysis. I have learn about it in the article by Cox and Popken (2008) recommended in this course, and I think it is a very interesting tool in RA. Should it be the case, I would include a mention to this statistical method.

Though you could argue that a classification tree is similar in some ways ETA and Classification tree analysis are different methods of analysis

You can find additional references in this paper and a mention to the rpart algorithm of the stastical software R. Perhaps, you can use it to improve your wiki. Good luck 570acm570acm (talk) 21:08, 9 November 2013 (UTC)

Thank you for the comments!570SJR (talk) 19:47, 13 November 2013 (UTC)[reply]

Your article looks good and there have been many comments. I have very few to add. Should Event Tree Analysis (ETA) is a forward, bottom up, logic modeling be logical modeling?

Can you add a link to binary?

Yes I can, good idea

Is something missing here? formatting? Unexpected or collateral damage as a result of tests*Failure of mission I'm not sure what failure of mission is doing right there.

I'm not sure what happened here thank you for pointing that out

Please check the format of your references.

I'm not sure what you mean on the formatting of the references. Could you explain more?

570lah (talk) 22:57, 21 November 2013 (UTC)[reply]

Thank you for the comments!!!570SJR (talk) 18:54, 24 November 2013 (UTC)[reply]

In the theory section, a probabilistic risk assessment use is stated; however in the methodologies and equation section there is a more deterministic approach described. Distinguishing between instances when a single point probability is used at each intervention point in a deterministic type assessment vs. a stochastic type assessment using probability distributions at each intervention point run with multiple iterations might be beneficial.

I agree that that could be useful but I don’t think that is done in event tree analysis if I am understanding you correctly. I think that you could run simulations to get different probabilities at each event for success or failure but usually the probability of failure comes from a fault tree analysis and then we are able to calculate the probability of success which is 1-pf.

Perhaps examples of the use of varying complexity ETA’s could be added to the page.

I’m not sure what you are saying here, do you mean to add a complex example with many branches or are you talking about using your previously described probability calculation in the ETA?

How is uncertainty addressed when an ETA is conducted?570ps (talk) 02:45, 11 November 2013 (UTC)

Generally uncertainty is accepted as this is an estimated approach but in some cases uncertainty is dealt with using fuzzy event tree analysis which I would believe is an entire wiki on its own. What do you guys think ? here is an article on it: http://www.sciencedirect.com/science/article/pii/S0165011498002887#

Huang, D., Chen, T., & Wang, M.-J. J. (2001). A fuzzy set approach for event tree analysis. Fuzzy Sets and Systems, 118(1), 153–165. doi:10.1016/S0165-0114(98)00288-7

Thank you for the feedback!! 570SJR (talk) 20:33, 13 November 2013 (UTC)[reply]

edits/recommendations Are:

"loss states" only considered to be negative actions and harm, although they can be naturally occurring? Like a flood for instance? Is that something that could be clarified?

Yes, to answer your question loss states are negative outcomes, a flood could be an outcome but more specifically would most likely be an intermediate event. For example a causal pathway I can think of off the top of my head it rains for 3 days (yes) a flood occurs (yes) houses are damaged in the flood (yes). Houses damaged would be the loss state or outcome given that it rained for 3 days and a flood occurred. I just added clarification in the theory section, I think that it is sufficient, let me know what you think.

Regarding the steps in the event tree analysis, are there programs that can be utilized to build the ETA? What is the simplest, easiest way to construct an ETA tree diagram?

I have added an answer to this in the software section due to the fact that using software will assist you in calculations and constructions of the event tree.

Can you identify some real time, real life scenarios or applications where these ETAs and diagrams have been created, besides from the nuclear power plant study?Good job, very detailed!570MAR (talk) 04:27, 14 November 2013 (UTC)

Yes I can !! :) but I do not know if those examples are thorough enough to be added to the wiki, for example they are all over some of the work Dr Nir Keren at ISU is doing but the nuclear power plant is one of the largest well known examples. I will see if I can find something to add that is used in a well-known example

Thank you for the feedback!! 570SJR (talk) 15:18, 15 November 2013 (UTC)[reply]

EB Russell: This is well-written. In the HISTORY section you reference WASH-1400 – can you expand on that or include a link about it?

I double checked and the first time wash-1400 is mentioned I have it linked to the wash-1400 wiki

In the section Event Tree Analysis In Risk Analysis: This sentence is a little confusing: Event Tree Analysis it is easy to see what pathway is creating the greatest possibility of failure for a specific system.

I changed the wording a little to make it easier to read. Were you referring to the terminology used in the sentence?

 — Preceding unsigned comment added by 570ebr (talk • contribs) 16:19, 21 November 2013 (UTC)[reply]

Thank you for the comments!!!570SJR (talk) 19:00, 24 November 2013 (UTC)[reply]

This is an interesting article and very well organized and written. Are you planning to simply add it in with the Event tree article? If not, a link should be provided at the least. The previous article specifically refers to Boolean logic, so maybe you should include this in the history or overview as well.

I agree I will add the link to the "event tree" page

It seems the first sentence of the history section would require a reference.

looking at the sentence I see it as fine, do you have a recommendation?

I appreciate the diagram and the steps on how to perform ETA. Also, I like the section pertinent to risk analysis, although no references are given anywhere in that paragraph.

I appreciate the comment, as for the references I was not able to find an article that states this. I have a professor who has written articles including event tree that states this but no written material, if you find one or know of one please let me know

The advantages and limitations may be better listed as a table as opposed to bullet points.

looking at that I'm not quite sure how I would list that as a table. Could you elaborate on what you were thinking for this?

Good work! Langleym (talk) 16:51, 21 November 2013 (UTC)[reply]

Thank you for the comments!!!570SJR (talk) 19:07, 24 November 2013 (UTC)[reply]

Looks great! Good organization, good use of wiki links, good picture of an event tree! Plus very concise but thorough, I think the bullet-points helped with that. The strengths and limitations sections were a good addition for anyone trying to decide if they want to use one. I like the inclusion of the "This was/is the part of an educational assignment"...may have to include that in mine! 570ADM (talk) 22:00, 22 November 2013 (UTC)[reply]

Thank you for the comments I'm glad you liked it570SJR (talk) 19:15, 24 November 2013 (UTC)[reply]

Adhithiya Charli Comments : Very interesting article and since I have not heard of ETA , it was a very good learning for me ! The steps for performing the ETA was very beneficial in understanding the concept. Good job ! Nice Topic ! - 570mac (talk) 19:21, 23 November 2013 (UTC)[reply]

Thank you !! I'm glad you liked it!570SJR (talk) 19:15, 24 November 2013 (UTC)[reply]

Comments from 570fmf

The article is concise and well written, as a suggestion I would delete the 3 examples of software since it could be considered as spam. I would only note the existence of the same and I will allow to the "users" to do their own research about this commercial services.570fmf (talk) 04:21, 24 November 2013 (UTC)[reply]

Thank you ! I appreciate the comments and the 3rd viewpoint on software I believe your point is valid! I will make the change570SJR (talk) 19:15, 24 November 2013 (UTC)-[reply]

Jie Luo-

cool topic and really, really well thought out and organized article! just one suggestion, since this is kinda over my head: i remember that we had this one article on drug-resistant campylobacter in Danish pigs, it was by alban 2007, that had a really nice event tree detailing every possible scenario of resistant campylobacter transmission. it might be worth considering to have it here if you want to tie in with biological risk assessment.Mercapto7 (talk) 04:54, 25 November 2013 (UTC)[reply]

That is a good idea for an example though I'm not sure that I need another example. As for including biological risk assessment that is another good suggestion but I would like to keep the risk assessment section broad as it can cover any type rather than stating specific types of risk assessments. Does anybody else have an opinion on this? I would like to hear more about thoughts on adding information from the mentioned article or rather from any other types of articles.

Thank you for the comments!!!570SJR (talk) 15:29, 25 November 2013 (UTC)[reply]

Yafei Wang

Your event tree analysis is very helpful for people who are taking hand doing an analysis. And also you introduced a software that should be of help. This event tree analysis should be a very broad topic and you introduced it very comprehensively although not very specifically. But that should be quite enough for this wiki entry.570wyf (talk) 19:54, 25 November 2013 (UTC)[reply]

Thank you for your comments!!!570SJR (talk) 22:55, 26 November 2013 (UTC)[reply]

The first section did a very nice job introducing the basic concept of ETA, however I thought the wording was cyclical at times. I reworded the intro as such:

"Event Tree Analysis (ETA) is a quantitative modeling technique used to assess a network of events and their relative positive or negative probable outcomes as well as performing overall system analysis. This specific analysis method might best be conceptualized as a “forward, bottom-up” technique that begins with a single initiating event and subsequently through diverging event-paths until reaching the terminal outcome. ETA can [1] facilitate systematic identification of positive and negative consequences which may occur while also [2] provide quantifiable measures of exposure and effect of specific events within a systeman activity system. ETA can be applied to a wide range of systems including but not limited to: nuclear power plants, spacecraft, and chemical plants. Utilizing ETA early in the design process may enable early identification of issues that could occur; this early identification allows may facilitate more proactive risk mitigation rather than reacting to problems/changes after they occur.[3] With this forward logic process use of ETA as a tool in risk assessment can help to prevent negative outcomes from occurring by providing a risk assessor with the probability of occurrence."

Now that you have reworded it I see what you mean, there is a minimal phrase that I would change in your edit your edit(bold above) thank you for the comment!! 570SJR (talk) 16:28, 27 November 2013 (UTC)[reply]

570mpt (talk) 15:09, 25 November 2013 (UTC)[reply]